如何检测用户之间的切换 [英] How to detect switching between users

问题描述

我已经运行在前台模式下的服务，我想以检测运行Android 4.2或以上的平板电脑用户会话之间切换。

有没有广播接收机我可以注册得到通知？

我已经注意到，谷歌音乐，只要其他用户会话选择在锁定屏幕上停止音乐播放。它是如何检测开关？

---

答案解释

感谢@CommonsWare为正确答案。我将解释多一点如何检测用户开关。

首先要注意的文件明确表示，接收机必须通过 Context.registerReceiver 注册。因此做这样的事情：

  UserSwitchReceiver接收器=新UserSwitchReceiver（）;
IntentFilter的过滤器=新的IntentFilter（）;
filter.addAction（Intent.ACTION_USER_BACKGROUND）;
filter.addAction（Intent.ACTION_USER_FOREGROUND）;
registerReceiver（接收机，过滤器）;
 

然后在接收器还可以检索用户ID。这里是一个小片段：

 公共类UserSwitchReceiver扩展的BroadcastReceiver {

私有静态最后字符串变量=UserSwitchReceiver;

    @覆盖
    公共无效的onReceive（上下文的背景下，意图意图）
    {
        布尔userSentBackground = intent.getAction（）等于（Intent.ACTION_USER_BACKGROUND）;
        布尔userSentForeground = intent.getAction（）等于（Intent.ACTION_USER_FOREGROUND）;
        Log.d（TAG，交换机接收用户发送的背景=+ userSentBackground +用户发送的前景=+ userSentForeground +;）;

        INT用户= intent.getExtras（）调用getInt（android.intent.extra.user_handle）;
        Log.d（TAG，用户=+用户）;
    }
}
 

解决方案

尝试<一href="http://developer.android.com/reference/android/content/Intent.html#ACTION_USER_FOREGROUND"><$c$c>ACTION_USER_FOREGROUND和<一href="http://developer.android.com/reference/android/content/Intent.html#ACTION_USER_BACKGROUND"><$c$c>ACTION_USER_BACKGROUND.我没有使用过他们，但他们分别加入API级别17，和他们的描述看起来可能会有所帮助。

I have a service running in foreground mode and I'd like to detect switching between user sessions on tablets running Android 4.2 or above.

Is there any broadcast receiver I can register to get notified?

I have noticed that Google Music stops the music playback as soon as another user session is chosen on the lock screen. How does it detect the switch?

---

ANSWER EXPLAINED

Thanks @CommonsWare for the correct answer. I will explain a bit more how to detect a user switch.

First be aware that the documentation explicitly says that receivers must be registered through Context.registerReceiver. Therefore do something like:

UserSwitchReceiver receiver = new UserSwitchReceiver();
IntentFilter filter = new IntentFilter();
filter.addAction( Intent.ACTION_USER_BACKGROUND );
filter.addAction( Intent.ACTION_USER_FOREGROUND );
registerReceiver( receiver, filter );

Then in the receiver you can also retrieve the user id. Here is a small snippet:

public class UserSwitchReceiver extends BroadcastReceiver {

private static final String TAG = "UserSwitchReceiver";

    @Override
    public void onReceive(Context context, Intent intent) 
    {
        boolean userSentBackground = intent.getAction().equals( Intent.ACTION_USER_BACKGROUND );
        boolean userSentForeground = intent.getAction().equals( Intent.ACTION_USER_FOREGROUND );
        Log.d( TAG, "Switch received. User sent background = " + userSentBackground + "; User sent foreground = " + userSentForeground + ";" );

        int user = intent.getExtras().getInt( "android.intent.extra.user_handle" );
        Log.d( TAG, "user = " + user );
    }
}

解决方案

Try ACTION_USER_FOREGROUND and ACTION_USER_BACKGROUND. I have not used them, but they were added in API Level 17, and their description seems like it may help.

这篇关于如何检测用户之间的切换的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！